U.S. patent application number 13/550172 was filed with the patent office on 2012-11-08 for barrier device for ostium of left atrial appendage.
This patent application is currently assigned to ATRITECH, INC.. Invention is credited to Robert G. Hauser, Robert A. Van Tassel.
Application Number | 20120283773 13/550172 |
Document ID | / |
Family ID | 23697195 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120283773 |
Kind Code |
A1 |
Van Tassel; Robert A. ; et
al. |
November 8, 2012 |
BARRIER DEVICE FOR OSTIUM OF LEFT ATRIAL APPENDAGE
Abstract
A membrane applied to the ostium of an atrial appendage for
blocking blood from entering the atrial appendage which can form
blood clots therein is disclosed. The membrane also prevents blood
clots in the atrial appendage from escaping therefrom and entering
the blood stream which can result in a blocked blood vessel,
leading to strokes and heart attacks. The membranes are
percutaneously installed in patients experiencing atrial
fibrillations and other heart conditions where thrombosis may form
in the atrial appendages.
Inventors: |
Van Tassel; Robert A.;
(Excelsior, MN) ; Hauser; Robert G.; (Long Lake,
MN) |
Assignee: |
ATRITECH, INC.
Plymouth
MN
|
Family ID: |
23697195 |
Appl. No.: |
13/550172 |
Filed: |
July 16, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10948217 |
Sep 24, 2004 |
8221445 |
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13550172 |
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10308032 |
Dec 3, 2002 |
6949113 |
|
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10948217 |
|
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09428008 |
Oct 27, 1999 |
6551303 |
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10308032 |
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Current U.S.
Class: |
606/213 |
Current CPC
Class: |
A61B 17/12022 20130101;
A61B 90/06 20160201; A61B 2017/00641 20130101; A61B 17/0057
20130101; A61F 2230/0069 20130101; A61B 17/12136 20130101; A61B
2017/00022 20130101; A61B 17/12122 20130101; A61F 2002/018
20130101; A61B 17/12131 20130101; A61B 17/12186 20130101; A61B
17/00234 20130101; A61F 2230/008 20130101; A61F 2/01 20130101; A61B
2017/00044 20130101; A61B 2090/064 20160201; A61B 2017/00243
20130101; A61B 2017/1205 20130101; A61F 2230/0006 20130101; A61B
17/12172 20130101; A61B 17/12159 20130101 |
Class at
Publication: |
606/213 |
International
Class: |
A61B 17/08 20060101
A61B017/08 |
Claims
1. (canceled)
2. A method of preventing atrial appendage thrombi from entering
the blood stream comprising: securing a membrane over an ostium of
an atrial appendage by extending an atrial appendage anchor into or
through a wall of the atrial appendage and providing a tether
between the atrial appendage anchor and the membrane, wherein the
tether is adapted to hold the membrane snuggly against the ostium
of the atrial appendage, further wherein the atrial appendage
anchor is adapted to expand upon release thereby resisting being
pulled out of or through the wall of the atrial appendage.
3. The method of claim 2, wherein the membrane is adapted to be
porous to blood and adapted to prevent thrombosis formed within the
atrial appendage from leaving the atrial appendage.
4. The method of claim 3, wherein the membrane is adapted to be
infiltrated with endothelial/endocardial cells thereby providing a
nonthrombogenic surface.
5. The method of claim 2, wherein the membrane is adapted to be
nonporous to blood and adapted to prevent thrombosis formed within
the atrial appendage from entering the blood stream.
6. The method of claim 2, wherein the membrane is adapted to be
adhesively affixed over the ostium of the atrial appendage.
7. The method of claim 2, wherein the atrial appendage anchor is a
disk.
8. The method of claim 2, wherein the tether is elastic.
9. The method of claim 2, wherein tether is a spring.
10. The method of claim 2, wherein the spring is a spiral
spring.
11. A device for preventing atrial appendage thrombi from entering
the blood stream comprising: a membrane sized and adapted to cover
an ostium of an atrial appendage; an atrial appendage anchor
adapted to expand following extension into or through a wall of the
atrial appendage thereby causing the atrial appendage anchor to
resist being pulled out of or through the wall of the atrial
appendage; and a tether connecting the atrial appendage anchor and
the membrane, said tether being adapted to hold the membrane
snuggly against the ostium of the atrial appendage.
12. The device of claim 11, wherein the membrane is adapted to be
porous to blood and adapted to prevent thrombosis formed within the
atrial appendage from leaving the atrial appendage.
13. The device of claim 12, wherein the membrane is adapted to be
infiltrated with endothelial/endocardial cells thereby providing a
nonthrombogenic surface.
14. The device of claim 11, wherein the membrane is adapted to be
nonporous to blood and adapted to prevent thrombosis formed within
the atrial appendage from entering the blood stream.
15. The device of claim 11, wherein the membrane is adapted to be
adhesively affixed over the ostium of the atrial appendage.
16. The device of claim 11, wherein the atrial appendage anchor is
a disk.
17. The device of claim 11, wherein the tether is elastic.
18. The device of claim 11, wherein tether is a spring.
19. The device of claim 11, wherein the spring is a spiral
spring.
20. The device of claim 11, wherein the tether at least partially
fills the atrial appendage.
21. The device of claim 11, further wherein the membrane is heparin
coated.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/948,217 filed Sep. 24, 2004, which is a division of U.S.
application Ser. No. 10/308,032 filed Dec. 3, 2002, now U.S. Pat.
No. 6,949,113, which is a division of U.S. application Ser. No.
09/428,008 filed Oct. 27, 1999, now U.S. Pat. No. 6,551,303.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a membrane or plug structure
applied to the ostium of an atrial appendage for preventing blood
flow and physical connection between an atrium of the heart and the
associated atrial appendage or appendages to isolate an atrial
appendage and prevent thrombus leaving therefrom.
[0004] 2. Description of the Related Art
[0005] There are a number of heart diseases (e.g. coronary artery
disease, mitral valve disease) that have various adverse effects on
the heart. An adverse effect of certain cardiac diseases, such as
mitral valve disease, is atrial (or auricular) fibrillation. Atrial
fibrillation way result in pooling of blood in the left atrial
appendage. Blood pooling may also be spontaneous. When blood pools
in the atrial appendage, blood clots can form and accumulate
therein, build upon themselves, and propagate out from the atrial
appendage into the atrium. These blood clots can then enter the
systemic or pulmonary circulations and cause serious problems if
they migrate from the atrial appendage and become free in the blood
stream and embolize distally into the arterial system. Similar
problems also occur when a blood clot extending from an atrial
appendage into an atrium breaks off and enters the blood supply.
Since blood from the left atrium and ventricle supply the heart and
brain, blood clots from the atrial appendages can obstruct blood
flow therein causing heart attacks, stokes or other organ ischemia.
It is therefore necessary to find a means of preventing blood clots
from forming in the atrial appendages and to prevent these blood
clots, once formed, from leaving the atrial appendages to the heart
lungs, brain or other circulations of the patient which can cause
heart attacks or strokes or other organ ischemia.
[0006] U.S. Pat. No. 5,865,791 relates to the reduction of regions
of blood stasis and ultimately thrombus formation in such regions,
particularly in the atrial appendages of patients with atrial
fibrillation. More specifically, the invention relates to
procedures and devices for affixing the atrial appendages in an
orientation that prevents subsequent formation of thrombus. The
invention removes the appendage from the atrium by pulling on it
and putting a loop around it to form a sack of the atrial appendage
and then cut off from the rest of the heart.
[0007] U.S. Pat. No. 5,306,234 relates to a method for surgically
closing the passage between the atrium and the atrial appendage or
severing the atrial appendage.
[0008] Other methods of treatment include surgically removing the
atrial appendages to prevent blood stasis in the atrial
appendages.
SUMMARY OF THE INVENTION
[0009] The invention provides a membrane or plug structure for
preventing blood from entering the atrial appendages to form blood
clots and prevents blood clots formed in the atrial appendages from
exiting therefrom which may cause heart attacks, strokes at other
embolic events. The membrane covers the ostium of the atrial
appendage ad effectively isolates it from the atrium. It may be
larger than the ostium of the appendage, and extend over an area
larger than the appendage ostium. It is percutaneously deed to the
ostium of the atrial appendage by a catheter and then expanded to
cover the ostium and has a means to attach the membrane over the
ostium. The membrane itself is may be porous or nonporous. In the
case of a porous membrane, it can become infiltrated with cells so
that it becomes a "living" structure, and can develop an
endothelial/endocardial lining to enable it in turn to become a
non-thrombogenic surface. There are many means for fixing the
membrane to cover the ostium of the atrial membrane. The membranes
attachment devices have a means for self-centering the membrane
over the appendage ostium. The membrane may be glued on, or have a
stents or prongs which pass through the ostium and extend into or
through the atrial appendage. Alternatively an anchor in the wall
of the atrial appendage may be tethered to the membrane for holding
the membrane in place. Springs may also extend between the anchor
and the membrane to hold the membrane against the ostium. The
membrane may also be connected to a tether, elastic tether or
spring and a placed through the atrial appendage wall for holding
the membrane against the ostium and may pull on the atrial
appendage such that its volume is reduced or eliminated, trapping
and isolating blood clots therein. Thrombin, activated fibrinogen,
or other biologic filler may be placed in the appendage after it
has been sealed, with the express purpose of clotting the blood in
the appendage, yet preventing clot from escaping the appendage.
[0010] Part of the device may involve a suction apparatus to remove
clots that are already in place. The membrane placement may require
closure of an atrial septal defect created by the placement of this
appendage occluder device.
[0011] Alternatively the membrane may be held in place by a coiled
spring filling the volume of the atrial appendage. The membrane may
also fill the atrial appendage itself preventing blood from
entering or blood clots from leaving.
[0012] The membrane itself may be porous or nonporous. In the case
of a porous membrane, it can become infiltrated with cells so that
it becomes a "living" structure, and can develop an
endothelial/endocardial lining to enable it in turn to become a
non-thrombogenic surface. It thus can develop an endothelium and
with time becomes highly biocompatible. It may be heparin coated to
prevent thrombus from forming on the membrane surface, immediately
after placement and until it infiltrates with cells and/or develops
an endothelial covering.
[0013] The device, when implanted in the atrial appendage, may also
have the ability to perform electrical monitoring of the heart.
This would consist of two or more electrical contacts placed apart
on the device, and connected to signal conditioning circuitry for
determination of cardiac features such as rhythm of the atria or
ventricles. Another sensor on the device could measure pressure of
the atria, atrial appendage, or ventricular end diastolic pressures
(left or right) through the open mitral or tricuspid valves. A
suitable telemetry system would be used to telemeter this important
electrical and hemodynamic information non-invasively outside the
patient. Also, memory could be present on the device in order to
record the information for later recovery via noninvasive
telemetry.
[0014] This device can also be used to close fistulae or
connections, elsewhere in the body, such as in the colon or
bronchopulmonary systems. Another application of the device would
be to seal and strengthen false aneuryms of the left ventricle by
holding the membrane against the false aneurysm. The same
principles apply, whereby the membrane is held against the fistulae
or false aneurysm, held in place by the spring or prong
mechanisms.
[0015] The device can also be used to chemically ablate the
myocardial tissue of the atrial appendage in order to help limit or
eliminate the electrical propagation of atrial fibrillation.
OBJECTS OF THE INVENTION
[0016] It is an object of the invention to reduce the volume of an
atrial appendage to reduce the size of the region for potential
blood stasis formation, and consequently the effective volume of
the affected atrium.
[0017] It is an object of the invention to measure hemodynamics
pressure (or flow), or electrical signals in the heart and
telemeter them outside the body for diagnosis or monitoring.
[0018] It is an object of the invention to be able to close
fistulae or connections elsewhere in the body, such as in the colon
or bronchopulmonary systems.
[0019] It is another object of the invention for the membrane to be
placed in a false aneurysm to strengthen this defect and to avoid
surgery.
[0020] It is an object of the invention to reduce the region of
static blood in the atrial appendages and hence the thrombogenicity
of the atrium.
[0021] It is an object of the invention to prevent blood clots from
forming in the atrial appendages.
[0022] It is an object of the invention to replace the ostium of
the atrial appendage with a non-thrombogenic, biocompatible surge
that prevents blood clots from forming.
[0023] It is an object of the invention to provide a porous
membrane surface which becomes lined with endothelial or
endocardial cells.
[0024] It is an object of the invention to isolate the atrial
appendage from the atrium proper and prevent communication through
which thrombus could migrate
[0025] It is an object of the invention to minimally invasively
prevent blood clots from forming in the atrial appendages and
escaping therefrom.
[0026] It is an object of the invention to provide a filter between
the atrium and atrial appendage to prevent blood clots from flowing
therebetween.
[0027] It is an object of the invention to fill the atrial
appendage with a material to prevent blood clots from leaving the
atrial appendage.
[0028] It is an object of the invention to remove thrombi from the
atrium via suction or other means.
[0029] It is an object of the invention to provide a means for
securing a membrane over the ostium of the atrial appendage that is
colonized with cells and provide a highly biocompatible surface
including but not limited to endothelialization.
[0030] It is an object of the invention to prevent thrombus by use
of heparin or other anti-thrombogenic substance on or eluted from
the membrane.
[0031] It is an object of the invention to seal the membrane with a
substance injected into the atrial appendage.
[0032] It is an object of the invention to clot the blood inside of
the atrial appendage after the membrane is in place with a
substance injected into the atrial appendage.
[0033] It is an object of the invention to inject a substance into
the sealed appendage to ablate the myocardial cells of the
appendage, in order to limit the propagation of atrial
fibrillation.
[0034] It is an object of the invention to ensure the membrane is
centered over the ostium of the atrial appendage.
[0035] It is an object of the invention to accurately place the
membrane over the ostium of the atrial appendage.
[0036] Other objects, advantages and novel features of the present
invention will become apparent from the following detailed
description of the invention when considered in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a partial cross sectional view of a heart showing
a catheter entering the left atrial appendage using a retrograde
procedure from the aorta.
[0038] FIG. 2 is a partial cross sectional view of a heart showing
a catheter entering the left atrial appendage using a transeptal
procedure from the femoral vein or superior vena cava.
[0039] FIG. 3 is a partial cross sectional view of a heart showing
a catheter entering the right atrial appendage from the jugular
vein or optionally from the femoral vein.
[0040] FIG. 4 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage.
[0041] FIG. 5 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage with a
porous membrane having flexible wire prongs with atraumatic bulbs
to hold the membrane in place and electronics built into the
membrane.
[0042] FIG. 6 is similar to FIG. 5 with the atraumatic bulbs
removed so that the flexible wire prongs may puncture the atrium
wall and secure the membrane to the atrial appendage and a
centering rim added to the membrane.
[0043] FIG. 7 is a partial cross sectional view of a portion of a
heart as in FIG. 5 with a stent portion between the membrane and
the prongs.
[0044] FIG. 8 is the same as FIG. 7 with the atraumatic bulbs
removed so that the flexible wire prongs may puncture the atrium
wall and secure the membrane to the atrial appendage.
[0045] FIG. 9 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage with a
porous membrane having a large expandable stent to hold the
membrane in place.
[0046] FIG. 10 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage having
an anchor and a tether to hold the membrane in place.
[0047] FIG. 11 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage having
an anchor and a spring to hold the membrane in place, a centering
rim on the membrane and a centering cable.
[0048] FIG. 12 is the same as FIG. 11 with the spring filling the
atrium to help hold the membrane in pace.
[0049] FIG. 13 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage with
the membrane adhesively being held in place.
[0050] FIG. 14 is a partial cross sectional view of a delivery
catheter having a disk, a spring and membrane therein.
[0051] FIG. 15 is a schematic view of a disk, spring and membrane
after being expanded out of the delivery catheter of FIG. 11.
[0052] FIG. 16 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage having
a disk, a membrane and a spring therebetween.
[0053] FIG. 17 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage shown
in a collapsed position.
[0054] FIG. 18 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage having
a disk, a spring, a membrane and vacuum in the catheter.
[0055] FIG. 19 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage having
a membrane material fill the atrial appendage.
[0056] FIG. 20 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
an umbrella folded for entering the atrial appendage.
[0057] FIG. 21 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
the umbrella opened in the atrial appendage to secure the umbrella
into the wall of the atrial appendage.
[0058] FIG. 22 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
the umbrella and membrane sealing the ostium of the atrial
appendage.
[0059] FIG. 23 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
a stent having a membrane for blocking the ostium of the atrial
appendage.
[0060] FIG. 24 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
the atrial appendage reduced to a minimum volume by a disk and
spring squeezing the appendage against a membrane.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] Although atrial fibrillation results in pooling of blood in
the left atrial appendage and the majority of use of the invention
is anticipated to be for the left atrial appendage the invention
may also be used on the right atrial appendage and in general for
any aperture in the body which needs to be blocked to prevent blood
from flowing therethrough or therefrom.
[0062] As shown in FIG. 4 a thrombus 30 may occur from pooling of
blood in the left atrial appendage 13 due to poor circulation of
blood therein when the patient experiences atrial fibrillation. To
prevent thrombus 30 from forming in the left atrial appendage 13 or
to prevent thrombosis formed therein from leaving and entering the
blood stream which may cause a heart attack, a stroke or ischemia,
a membrane 40 is placed across the ostium 20 of the atrial
appendage 13. The membrane 40 can be made of Teflon.RTM., felt,
Dacron.RTM., silicone urethane, Gortex.RTM., metal fibers or
biocompatible polymers.
[0063] The membrane 40 may be a porous membrane. Porous membranes
may consist of a biocompatible polymer which is porous, having pore
sizes ranging from 20-100 microns. The pores may also be larger or
smaller in rare cases. The membrane may also be a porous metal or a
metal mesh of fine fibers which permit ingrowth of cells and
covering with endothelial cells. The membrane may be coated with
anticoagulant, or elute the anticoagulant.
[0064] The porous membrane colonizes with cells from the heart and
so walls off the ostium 20 so that blood can not flow into the left
atrial appendage 13 to form thrombus 30 and more importantly no
thrombus 30 formed can leave the left atrial appendage 13 to cause
heart attacks, strokes or ischemia.
[0065] The membrane 40 placed over the ostium 20 should be
antithrombotic. In order to make the membrane antithrombotic
heparin or other anticoagulants or antiplatelet agent may be used
on the membrane 40.
[0066] When porous membranes 40 are used which have an ingrowth of
cells covering the membrane with endothelial cells the endothelial
cells present a smooth cellular wall covering the membrane which
prevents thrombosis from occurring at the membrane.
[0067] When blood pools in the left atrial appendage 13, thrombus
30 (blood clot) can accumulate therein, build upon themselves, and
propagate out from the left atrial appendage 13 into the left
atrium 11 entering the blood stream, leaving the heart and can
block blood flow to the heart, brain, other organs, or peripheral
vessels if it becomes lodged in the arteries thereof.
[0068] FIGS. 1 and 2 show a cross section of a human heart showing
a thrombus 30 in the left atrial appendage 13. The figures also
show the atrial appendage ostium 20 which is to have a membrane 40
placed over it to prevent the thrombus 30 from escaping out of the
atrial appendage 13 into the left atrium 11 and thus into the blood
stream, which could cause a stroke, a heart attack or ischemia. The
membrane 40 also prevents blood from entering the left atrial
appendage 13 where it could pool due to poor circulation and become
a thrombus.
[0069] FIG. 3 shows a cross section of a human heart showing a
thrombus 30 in the right atrial appendage 23. The right atrial
appendage 23 can be treated in the same manner as the left atrial
appendage 13.
[0070] FIG. 4 shows a cross section of the left atrium 11, the
ostium 20 and the left atrial appendage 13 having a thrombus 30
therein.
[0071] FIG. 5 shows a first embodiment of the invention wherein the
porous membrane 40 has a plurality of flexible prongs 50 which may
be made from a shape memory alloy, such as Nitinol.RTM., for
retaining a predisposed shape. The prongs 50 may be atraumatic so
that they do not perforate the left atrial appendage 13. The prongs
50 may have atraumatic bulbs 55 on their tips so that the tips of
the prongs 50 will not perforate the left atrial appendage 13.
Nitinol.RTM. has the property of being able to be placed in a
catheter in a compact configuration and then expanded when released
from the catheter to a predetermined memory shape. The shape
selected may be for the prongs 50 to curve around the lip of the
ostium 20 and then hug the sides of the left atrial appendage 13.
In this manner the membrane 40 will securely block the ostium 20
preventing blood from entering and particularly for preventing
thrombosis 30 from leaving the left atrial appendage 13.
[0072] The membrane 40 is self centering over the ostium 20 of the
left atrial appendage 13, by placing the prongs 50 in a circle
around the membrane 40 such that the prongs 50 fit against the wall
of the left atrial appendage 13 of or within the lumen of the
ostium 20 to center the membrane 40 over the ostium 20. The
membrane 40 may also be centered by a centering rim 65 (see FIG. 6)
attached to the back (appendage) side of the membrane 40 that
protrudes into the ostium 20 for centering. The centering rim 65
has a diameter of less than the diameter of the membrane 40. The
centering means may also consist of a series of centering cables 66
(see FIG. 11) which attach to a spring 90 or tether 85 from the
centering rim 65 or the membrane 40, to assure that centering
occurs with placement.
[0073] Optionally electronics, such as sensors 300 and chips 310,
built into the membrane may be used to provide data about
hemodynamics pressure, flow rates, temperature, heart rates, and
electrical signals in the heart. When the membrane is placed in the
left atrial appendage 13 the sensors 300 may measure pressures in
the atria or atrial appendage. The sensors may also measure
ventricular end diastolic pressures through the open mitral or
cuspid valves. Other information about the heart may be gathered
such as noise from accelerometers to detect leakage, valve
efficiency, activity levels of the patient and other noise related
date. The sensors 300 may also be blood oxygen sensors. The chip
310 may use telemetry to transmit the information gathered by the
sensors 300 and processed or stored by the chip 310 to receiving
devices to aid in the treatment of the patient.
[0074] In FIG. 6 the protective bulbs 55 are removed from the
flexible prongs 50 of FIG. 5 such that flexible prongs 50 puncture
the walls of the left atrial appendage 13 and secure the membrane
40 in place. The flexible prongs 50 may penetrate into the atrial
appendage wall or extend through the atrial appendage wall. The
prongs may have based ends 51 to prevent the prongs from
withdrawing from the atrial appendage wall.
[0075] The membrane 40 has centering rim 65 attached for centering
the membrane in the ostium 20 and marker 320 in the membrane 40 for
observing the position of the membrane while it is being inserted.
The marker may be used for x-ray or ultrasound observation.
[0076] Although Nitinol.RTM. was cited above as a type of shape
memory alloy prong material which can be used, any type, memory
alloy may be used. Such alloys tend to have a temperature induced
phase change which will cause the material to have a preferred
configuration when heated above a certain transition temperature.
Other metals which may be used as prongs include corrosion
resistant spring metals such as Elgiloy.RTM. or spring tempered
steel.
[0077] Another embodiment of the invention is shown in FIG. 7. It
is similar to the embodiment shown in FIG. 5. The embodiment in
FIG. 7 has a stent 60 attached to the membrane 40 for expanding in
the ostium 20 helping to secure the membrane 40 thereto. The prongs
50 operate in the same manner as in FIG. 5 hugging the inner walls
of the left atrial membrane 13 to secure the membrane 40 to cover
the ostium 20. The stent 60 may also be made from Nitinol.RTM.,
Elgiloy.RTM. or another expandable spring loaded or balloon
expandable material.
[0078] The membrane 40 may be self centering over the ostium 20 of
the left 13 atrial appendage, by placing the stent 50 into the
ostium wherein the stent plugs the ostium with the membrane 40
centered in the stent. Further the prongs 50 fit against the wall
of the left atrial appendage 13 of or within the lumen of the
ostium 20 to center the membrane 40 over the ostium 20.
[0079] In FIG. 8 the protective bulbs 55 are removed from the
flexible prongs 50 of FIG. 7 such that flexible prongs 50 puncture
the walls of the left atrial appendage 13 and secure the membrane
40 in place. The flexible prongs 50 may penetrate into the atrial
appendage wall or extend through the atrial appendage wall. The
prongs may have barbed ends 51 to prevent the prongs from
withdrawing from the atrial appendage wall.
[0080] In the embodiment shown in FIG. 9 a larger expandable stent
70 is used to both engage the sides of the ostium 20 and hug the
inside walls of the left atrial membrane 13. Again the stent may be
made of Nitinol.RTM., Elgiloy.RTM. or other material which may be
delivered in a catheter and expanded to the proper size and shape
to securely hold the membrane 40 over the ostium 20 to prevent
blood from entering the left atrial appendage 13 and for preventing
thrombosis 30 from exiting.
[0081] FIG. 10 shows another embodiment of the invention wherein
the membrane 40 is secured over the ostium 20 by means of an anchor
80 which is driven into or through the wall of the left atrial
appendage 13 and secured therein by the surface area of the anchor
so that it will not pull out of or through the wall of the left
atrial appendage 13 or cause embolism from the left atrial
appendage 13. A tether 85 is attached to the anchor 80 and to the
membrane 40 to secure the membrane 40 snuggly against the ostium
20. A substance 270 such as thrombin, activated fibrinogen, or
other biologic filler may be placed in the left atrial appendage 13
by injection through a catheter after the membrane 40 is in place
such that blood is clotted in the atrial appendage so that it can
not escape. The device delivery catheter itself may have a port for
this injection. The port may also be used to inject contrast such
as echocardiographic contrast that can be immediately visualized,
and examined to determine whether there is a good seal between the
ostium of the appendage and the device. The substance 270 injected
into the atrial appendage may also be a sealant or filler to seal
the membrane against leakage from the atrial appendage. The sealant
material, filler material or blood clotting material may be used
with any of the embodiments of the invention.
[0082] In another embodiment the catheter may inject a chemical
ablation agent such as ethanol to ablate the myocardial cells in
the sealed off atrial appendage 13 and thus limit atrial
fibrillation by limiting or eliminating electrical propagation in
the atrial appendage.
[0083] FIG. 11 shows another embodiment of the invention wherein
membrane 40 has a spiral spring 90 in addition to the anchor 80.
The spiral spring 90 can be used in conjunction with or separately
from the tether 85 to pull the membrane 40 against the ostium 20.
Although a spiral spring 90 has been shown in FIG. 9 the shape used
may be oval, cylindrical, oblong, or other shape to connect the
anchor 80 to the membrane 40. In another embodiment shown in FIG.
12 the spiral spring 90 may fill the volume of the left atrial
appendage 13 securing the membrane 40 to the ostium 20. The spiral
spring 90 filling the left atrial appendage 13 may also have an
anchor 80 and tether 85 to help secure the membrane 40 to the
ostium 20. Alternatively centering rim 65 may be used as shown in
FIG. 11 to center the membrane 40 over ostium 20 of left atrial
appendage 13. Centering cables 66 connected to spring 90 and either
membrane 40 or centering rim 65 may also be used to center the
membrane 40 over the ostium 20.
[0084] FIG. 13 shows yet another means of securing the membrane 40
over the ostium 20. In this embodiment membrane 40 is directly
attached to the ostium 20 by an adhesive 100.
[0085] FIG. 14 shows a delivery catheter 125 containing a collapsed
porous membrane 40 and a collapsed disk 130 connected to the porous
membrane 40 by a spring 90 on catheter 21. The disk 130 may be made
of a flexible woven metal or a flexible woven metal with a thin
porous polymer sandwiched inside. Disk 130 may also be a polymer
weave. The disk 130 is flexible and compresses or folds so it fits
into the delivery catheter 125 and expands to its desired shape
after release from the delivery catheter 125. Similarly membrane 40
compresses or folds to fit into the delivery catheter 125 and
expands to its desired shape after release. FIG. 15 shows the
porous membrane 40, disk 130 and spring 90 from FIG. 14 in an
expanded configuration outside of the delivery catheter 125.
[0086] FIG. 15 shows the spring 90 connecting the porous membrane
40 and the disk 130 for urging them together. In other embodiments
an elastic tether or a tether with teeth and a pawl on the porous
membrane 40 to form a ratchet can also be used to pull the porous
membrane 40 and the disk 130 together.
[0087] FIG. 16 shows the device of FIG. 15 applied to the left
atrial appendage 13 having thrombus 30. After the device is applied
the spring 90, pulls the disk 130 toward the porous membrane 40
collapsing the left atrial appendage 13 and trapping the thrombus
30 therein as shown in FIG. 17.
[0088] FIG. 18 shows an alternate embodiment of the device in FIGS.
16 and 17 wherein the catheter 21 is equipped with a vacuum 140 for
sucking out blood and thrombosis 30 found in the left atrial
appendage 13. The vacuum 140 will help collapse the left atrial
appendage 13 such that spring 90 need not be as large as in FIG.
16.
[0089] FIG. 19 shows an alternative embodiment of the device where
the membrane 150 is inserted into the left atrial appendage 13 and
fills it securing the membrane 150 therein. The membrane 150 may be
delivered in a catheter as a compressed material and expanded in
the atrial appendage 13 or be delivered in a liquid form which will
fill the atrial appendage and be transformed into a membrane by
curing with another chemical delivered by the catheter or with the
aid of a UV light supplied through a fiber optic cable in the
catheter 21. By filling the left atrial appendage 13 with a
membrane material 150 no blood can enter to pool and become a
thrombus 30 and no thrombus 30 can exit to cause heart attacks,
strokes and ischemia.
[0090] FIGS. 20-22 show another embodiment of the invention using
an umbrella principle for securing the membrane 40 against the
ostium 20. FIG. 17 shows closed umbrella struts 160 entering the
ostium 20 of left atrial appendage 13. The membrane 40 is some
distance back from the umbrella struts 160 at the bottom of the
range of teeth 195 on pole 170. FIG. 21 shows the umbrella struts
inside of the left atrial appendage 13 with the struts 160 open.
Umbrella opening structure 175 on pole 170 pushes the struts out to
the umbrella open position. The umbrella opening structure 175 can
be pushed to the open position or have a spring loaded mechanism to
push the struts 160 to the open position. The ends of the umbrella
struts 160 engage the left atrial appendage wall around the ostium
20 and prevent the umbrella from being withdrawn from the left
atrial appendage 13. The ends of the umbrella struts 160 that
engage the atrial appendage wall may be blunted or have bulbs on
the tips or have padding so as not to puncture the left atrial
appendage 13. FIG. 22 shows the membrane 40 drawn up against the
ostium 20 by ratcheting the membrane along pole 170. The pawl
mechanism 200 engages teeth 195 on pole 170 and is moved forward to
snuggly block the ostium 20 with the membrane 40.
[0091] FIG. 23 shows a stent 260 applied to the ostium 20 of left
atrial appendage 13. The stent 260 expands after leaving a delivery
catheter such that the wall of the stent secures the stent by
pressure to the ostium 20. Membrane 240 folds or is compressed into
the delivery catheter and expands as the stent 260 expands and
lodges in the ostium 20 of the left atrial appendage 13.
[0092] FIG. 24 shows the left atrial appendage 13 compressed such
that the volume of the atrial appendage is reduced to almost
nothing. With the volume reduced the atrial appendage will not have
a large volume of blood which can produce a thrombus. In the
embodiment shown disk 130 and spring 90 pull the left atrial
appendage 13 toward membrane 40. Although FIG. 24 shows the use of
a disk 130 and spring 90 to act on the left appendage any method to
reduce the volume of the atrial appendage as much as possible may
be used. In addition to physically reducing the volume a substance
270 may be injected into the appendage to further limit its volume,
or to clot the blood already present therein.
[0093] As shown in FIG. 24 the membrane 40 is much larger than the
ostium 20. The over size membrane 40 may be used in all embodiments
to ensure that the ostium 20 is completely blocked.
[0094] The devices described above may be percutaneously delivered
to the left and tight atrial appendages 13, 23 respectively. The
devices may have materials in them which enhance vision or imaging
by ultrasound, x-ray or other means making it easier for the device
to be implanted and accurately centered over the ostium 20 of the
atrial appendage 13. This may consist of small beads placed
strategically on the membrane, the connecting elements, or on the
anchors. Referring to FIG. 1 catheter 21 is seen entering the heart
by way of the aorta 12 to the left ventricle 16 passing through the
mitral valve 17 and then entering the left atrial appendage 13 to
apply the porous membrane 40 in one of the embodiments as disclosed
above. In FIG. 2 the catheter 21 enters the heart from the femoral
vein, passes through the inferior vena cava 18 to the right atrium
and then passes through the fossa ovalis 19 or through the septum
29 into the left atrium 11 and then approaches the left atrial
appendage 13 to apply the porous membrane 40 thereto. FIG. 3 shows
the catheter 21 being applied to the right atrial appendage 23.
Catheter 21 may enter the heart through the jugular vein 28 or the
femoral vein to the inferior vena cava 18.
[0095] It should be understood that the invention may be practiced
with numerous means of attaching the membrane 40 to cover the
ostium 20 of the atrial appendages 13 and 23. Any combination of
the attachment means with adhesives, prongs, stents, anchors,
disks, tethers or springs may be used. The membrane may also be
inside of the atrial appendages 13 and 23, or may penetrate the
atrial appendage and provide a means to securely lock the membrane
device into place. Other means of providing a membrane for blocking
blood flow into and blood clots out of the atrial appendages not
listed may also be used. A substance may be injected into the
appendage to limit its volume, or to clot the blood already
present.
[0096] In all of the above embodiments the blood of the appendage
may be facilitated to clot in order to form a large, immobile mass.
Alternatively, the appendage may be filled with any substance that
will occupy volume. Examples are fibrin, prosthetic polymers
(PLLA). Silicone, or a balloon that is delivered and remains in
place for long periods of time.
[0097] All of the above embodiments shown and discussed for the
left atrial appendage 13 are also useable on the right atrial
appendage 23. Further the invention may be used to close fistulae
or connections elsewhere in the body such as the colon or
bronchopulmonary systems. The invention may also be used to seal
false aneurysms. When the membrane is placed in a false aneurysm it
will strengthen the defect and may help to avoid surgery.
[0098] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that, within the scope of the appended
claims, the invention may be practiced otherwise than as
specifically described
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